The Eighteen Angels of High Saint Academy

On a certain day of a certain year and a certain month, God summoned his eighteen angels and asked them to go to the High Saint College to help all the students there. Each angel had a mission that belonged only to him. God asked them to complete their mission within three months. When the seventeen angels completed their missions one after another, the eighteenth angel was still unable to complete the mission, and the time was almost up. . . Can it still be an angel? Or be destroyed together with the people in the academy. . .